Coming off victory in the West Virginia primary, his 20th win of the primary season, Sanders’ campaign said on May 11 the Democratic Party would be courting “disaster” if it nominates Clinton as its presidential nominee.

Democratic presidential candidate Sen. Bernie Sanders. /AP

“For months, Bernie Sanders has out-polled Hillary Clinton against Donald Trump, and often by extraordinarily large margins. Because we must do everything we can to defeat Trump in November, our mission is to win as many pledged delegates as we can between now and June 14,” Sanders campaign manager Jeff Weaver said.

“Then we’re going to have a contested convention where the Democratic Party must decide if they want the candidate with the momentum who is best positioned to beat Trump, or if they are willing to roll the dice and court disaster simply to protect the status quo for the political and financial establishment of this country.”

Weaver cited recent polls showing Clinton virtually tied with Trump in the key battleground states of Ohio, Pennsylvania and Florida.

Weaver said the Democratic Party — and its superdelegates who are free to support either candidate — must reject Clinton and embrace Sanders, or face a crushing defeat in November.

“Some people say we do better against Trump because we haven’t faced the Republican attack machine yet. But we’ve been told our goals for the future are utopian, and that our plans would raise taxes on middle class families. We just never thought those attacks would come in a Democratic primary. Yet somehow we keep winning,” Weaver said.

“We are the best chance to defeat Trump because people united can never be defeated. That is why we must keep fighting.”

Meanwhile, Trump met with House Speaker Paul Ryan in Washington on May 12.

The Trump campaign released a joint statement from the candidate and the speaker:

“The United States cannot afford another four years of the Obama White House, which is what Hillary Clinton represents. That is why it’s critical that Republicans unite around our shared principles, advance a conservative agenda, and do all we can to win this fall.

“With that focus, we had a great conversation this morning. While we were honest about our few differences, we recognize that there are also many important areas of common ground. We will be having additional discussions, but remain confident there’s a great opportunity to unify our party and win this fall, and we are totally committed to working together to achieve that goal.

“We are extremely proud of the fact that many millions of new voters have entered the primary system, far more than ever before in the Republican Party’s history. This was our first meeting, but it was a very positive step toward unification.”